Elevator system



Sept 20, 1949. H. w. WILLIAMS 2,482,529

ELEVATOR SYSTEM Filed Oct. '7, 1946 n '7 Sheets-Sheet l BUC abcde ,fg/:1Q

Sept 20, 1949. H. w. WILLIAMS 2,482,529

ELEVATOR SYSTEM Filed Oct. 7, 1946 7 Sheets-Sheet 2 35/ EE' BMI WITNEssEs: INVENTORL- 5 E? 3 fbm/dMh//y//Om Sept. 2o, 1,949.

Ffiled Oct. 7, 1946 2p oz ITNESSES:

-H. W. WILLIAMS ELEVATOR SYSTEM 7 Sheets-Sheet 4 BMS 3X3 5/2 INVENTOR ATTORNEY Hara/07% h//W/Om Sept. 20, 1949. H. w. 'WILLIAMS t 2,432,529

y ELEVATOR SYSTEM v Filed oct. 7, 194e 7 sheets-sheet 6 GUEB 396 WITNESSESI Y i INVENTOR i4 ,ggg /bm/dMM//f-m v/ oRNEY H. W. WILLIAMS ELEVATOR SYSTEM Sept. 20, 1949.

7 Sheets-Sheet 7 Filed Oct. 7, 1946 wmmssEs-- trol means which will, when a loaded-"oai" b`y- 20 'div'idu'altoeahieartvlllb'e give'rlthefsameirferpasses" a floor having ak S'0pca11,"'ause 4'Some ence@limractersleircebtftiiatstheapearamsE #for ther "Car'to promptly answersch Stor c'alby cai-fB=vi11-` begaven-theiprflzeltoiindicatethatrit stopping" at the 'bypassed I'floor'. is for'fcar AB'lin's'teaiifof foremh 'Afurtherbbjectis to'providea eoritrlsystem W t .l for levatorcars"inwhich the bypassing-bf 'a 25 Appamtusmdwzdual to 'car 'A fio'orbyacar will', when a predeterminednumber #acari buttons of" calls:v accumulate atfiloors 'in' a`A predetermined rac-elearmutton holding c'oils servicedemandzone," automatically-cause *Some D-dovvn switch other "'car' to stop vat isuclroors and' answer' 'the E-Slowf'dowmindu'ctor..lre1ay stopc'allsthereat. y 30 F-estoppingxnduetomelay A furtherobjectsto provide afl/control system G-nductor :holdingarelay invvhi'ch any'car may Vloe automaticallywau's'd fo H1highar callrelay give spccial'service to-*floors* having unanswered Jhghrcall revemingrelay stop`A calls. K-+.hfighzloor;eal1me1ay I'Afstill Efurther object is to "providea"control 35 L-supply conductors system Whiehlwll,- whena down 'f car lbypassesla M-s-:carirunningsrelay down` stop call at 'av "floor, causel an up* moving Painduoton-plates car'to'stop, reverse and' answer thelunanswere'd R4L-resistors down call. S-efloor-fcall stopping relay Other objects of my invention vill-bec`ome=evi 40 Tui-'ear calllstoppngrelay dent `yfrom the following frieten-led description UQ-upldirectiorr switch taken vin fconjunction Awvithlthe -a'ceompaniing V-highaspeedrrelay I drawings, in which: W-iipdirectonepreierence relay vv"Figure 1 lis Vadiagramma'ticfrepresentation'ff X-down direction preferenceelay airelevatorfsystem embodyingmyiriveri'tion; 45 Yav-special'servi-cerelays TFigJZ-is adiagrammatic representation oflf'the 21-byfpassswitch www "'Citact '.Segmenfts and the "mmg impurezas"eommonffwrzz am brushes onaifloorselector for -oneof the -cars H ,m Y* embodiedin Figs 1;-with'the brushes fdisposdff'in DBP-.down 110050511 tailoring relays the position theyfwiii take-when the caresse-ripped 50 URP-upfloor call 'storing' "relays 3 II to a counterweight I2. The sheave Il is mounted for rotation by a shaft I3 driven by a motor I4. A brake I5 of the usual spring-applied, electro-magnetically-released type is provided for stopping rotation of the sheave I I when the motor I4 is deenergized.

A iioor selector I6, of any suitable type, is provided for connecting the various electrical circuits of the system in accordance with the position of car A. The shaft I3 is extended to operate a brush carriage I'I on the floor selector IS by mechanically rotating a screw-threaded shaft I8 on which the carriage is mounted. The carriage I'I is provided with a number of brushes which are disposed, upon movement of the car, to successively engage stationary contacts arranged in rows on the selector in position to correspond to the floors of the building. For simplicity, only two brushes, up brush 32 and down brush 42, and two rows of contact segments, up segments b2 and down segments g2, etc., disposed to be engaged by them are illustrated in Fig. 1, but it will be understood that in the system to be described herein, as well as in practice, a much larger number of brushes and rows of contact segments is required. Owing to the friction between the carriage II and the screw-threaded shaft I8, the up brushes will engage the up segments only while the car is going up and the down brushes will engage the down segments only while the car is going down. Other forms of selectors may be substituted for the selector shown, if desired.

A starting switch CS is mounted in the car to be operated by the attendant to start the car. When the car switch is rotated anticlockwise, it closes its contacts CSI to start the car for the direction for which it is conditioned to operate. When the car switch is centered, it leaves the control system of the car in such condition that the car can be stopped by operation of hall buttons at the floor landings or by stop buttons in the car. It is to be understood that the car may be operated by the car switch or that any suitable control means may be substituted for the car switch. The illustration o the car switch is used for simplicity in describing the system.

The car buttons 2c, etc. (one for each oor) are mounted in the car, so that the attendant may, by operating them, cause the car to stop automatically at any ocr. The direction of operation of the car is automatically controlled by direction relays W and X, as will be described in connection with Fig. 3.

The hall buttons are mounted at the floor landings, in order that waiting passengers may cause the cars to stop thereat. An up button and a. down button are provided at each floor intermediate the terminals. A down button is disposed at the top terminal and an up button at the bottom terminal. Fig. l illustrates only the up hall call button 2U and the down hall call 2D for the second floor.

In order to automatically effect accurate stopping of car A at the floors in response to operation of the car stopping buttons 2c, etc., or the hall call buttons 2U, 2D, etc., a slow-down inductor relay E and a stopping inductor relay F are mounted on the car in position to cooperate with suitable inductor plates of iron or other magnetic material, mounted in the hatchway adjacent to each floor. Only the up plates UEP and UFP and the down plates DEP and DFP for the second floor are illustrated. Similar plates are provided for up direction stops.

-Y for the high call relay to be described later.

for each floor, except that the top terminal has only up plates and the bottom terminal only down plates.

The inductor relays E and F, when their coils are energized, have normally incomplete magnetic circuits which are successively completed by the inductor plates as the car approaches a floor at which a stop is to be made. These relays are so designed that energization of their operating coils will not produce operation of their contacts until the relay is brought opposite its inductor plate, thereby completing the relay magnetic circuit. Upon operation of the relay contacts (such as EI or E2) they remain in operated condition until the relay operating coil is deenergized, even though the inductor relay moves away from the position opposite the inductor plate which completed its magnetic circuit. The plates should be so spaced in the hatchway as to provide desirable distances for slowdown and stopping of the cars at the floors. Other methods of controlling slowing down and stopping of the cars may be used if desired.

A push-button switch 21 is provided in car A to permit the attendant to by-pass the calls ahead of his car when it is loaded or whenever he desires to operate the car straight through. This switch is also provided with additional contacts for calling into operation certain relays when special service demands exist.

Apparatus in Fig. 2

Fig. 2 illustrates an enlarged view of the iloor selector I6 of Fig. 1. In this ligure, the various stationary contact segments are represented by rectangles and the contacting brushes by small circles. The brush carriage I'I is shown by dotted lines in the position it occupies when its car is at the third iloor.

The contact segments a2 to a1 inclusive on the iloor selector are disposed to be successively engaged by the brush 30 to control the high car call relay H and by the brush 3| for completing stop circuits set up by the call push-bottoms in the car The brush 30 should be long enough to bridge adjacent contact segments.

The contact segments b2 to h6 inclusive and the brush 32 are for connecting the circuits of the hall stop buttons 2U, etc., for up stops. The up contact segments c2 to c6 inclusive and the brush 33 are provided for connecting circuits for cancelling stop calls registered by the up hall call buttons 2U, etc. The up contact segments d2 to d'I inclusive and the brush 34 connect circuits The contact segments e2 to e1 inclusive and the brush 35 connect circuits whereby a car may cancel special service demand calls when it answers such special service demands.

The down cancel contact segments f2 etc., and brush 40, the down floor call contact segments g2, etc., and brush 4I, and the down car call contact segments h2 etc., and brush 42 are provided for connecting circuits for the down direction in the same manner as described for the up direction. The down contact segments i2 through il and brush 43 connect circuits whereby a down car which by-passes a stop call at a floor may set up a service demand to stop an up car.

On the right-hand side ofthe iioor selector, a series of switches 52 to 56 are illustrated as disposed to be operated by a cam 49 on the carriage I'I as it moves from its floor to floor position, for the purpose of controlling the high car call circuit set up by brush 34.

call is registered is energized as long as the call exists.

A car stopping relay S is shown as connected to the up brush 32 engaging segments b2, etc., and the down brush 42 engaging segment g2, etc. When the car approaches a floor in a direction for which a call is registered, the crorresponding brush engages the energized contact segment for that floor and that direction and thereby causes the relay S to be energized, which, in turn, energizes the inductor relays F and E of that car to effect the stopping of that car at that floor.

A cancellation coil is wound in opposition to each call registering coil and connected to the cancellation contact segments on the iioor selector. The up cancellation coils are designated as ZURN, etc., and are connected to the up segments c2, etc., and the down cancellation coils as 2DRN, etc., connected to the down segments f2, etc. As the brush 33 moves over the segments c2, etc., and the brush 4i moves over the segments f2, etc., they energize the cancellation coil for any floor at which the car stops to answer a stop call, in accordance with its direction of operation.

Apparatus in Fig. 5

The cars and their control apparatus are provided for operation, under normal conditions, as a high call reversal system in which the cars stop for up calls on their up trips but automatically stop and reverse at the highest down call when there is no service required above the highest down call. The high floor call relay K and the high call reversing relay J effect this result.

The high floor call relay K of car A controls the operation of the high call reversing relay J for that car in accordance with the existence or non-existence of registered oor calls above it. A high call circuit 50 is provided for connecting the relays K or BK to the supply conductor L+5. The high call circuit 5U includes back contacts of the up and down call registering relays arranged in series relation according to the natural sequence of the floors and is connected at floor points with the contact segments di, d2, etc. Consequently, when car A is traveling upwardly, its relay K will not be energized as long as a call exists at any floor above the floor of the contact segment on which the brush 34 rests, but as soon as the brush reaches a segment for a floor with no stored call above it, a circuit for the relay K is completed to cause it to energize the relay J.

The high call reversing relay J is operated by the relay K under certain conditions to so prepare the circuits of car A that it will stop and reverse its direction of operation at the oor corresponding to the highest registered down call in the high zone when it is running upwardly and has no stop call registered on its car buttons for a floor above the highest down call. In such cases, relay J stops the car by closing its contacts J l in the circuit of the inductor relays E and F (Fig. 3) and it then reverses it by opening its contacts J2 in the circuit of the up direction preference relay W (Fig. 3).

However, there are times when the number of down calls becomes so large that some of the down cars become so loaded that they cannot take on any more down passengers and are forced to by-pass further down floors, thus leaving the down passengers thereat without prompt service. Therefore, the system is also provided with an auxiliary circuit 5l for the relays K and BK and a plurality of service demand relays ZY, etc., one for each oor, for cooperation with the by-pass means so as to cause an unloaded up moving car to stop and reverse at the highest down call at or below .a oor at which a by-pass is operated to take on down passengers thereat without continuing its up trip.

The service demand relays 2Y, etc., are connected for energization by the operation of the by-pass button 21 in a car when it makes a down stop at a floor and becomes so loaded that it cannot take on any more passengers. When a. service demand relay (3Y, etc.) is energized, it opens contacts, such as 3Y2, and closes contacts, such as 3YI, in the service demand circuit 5l to cause energization of the high floor call relay K of the next unloaded up moving car for stopping and reversing that car at the oor of the highest operated down call device at or below the oor at which the bypass was operated.

Each service demand relay (2Y, etc.) is provided with a cancelling coil (2YN, etc.) so that a, car answering a service demand will cause the demand relay (2Y, etc.) to be restored to its normal condition. Although the drawings show a service demand relay for each floor above the lower terminal, they may be omitted from the upper floors where it is not desired to have a. bypass effective to reverse the next up empty car, if desired.

In many installations, it is desirable to prevent the service demand relays from causing the stopping and reversing of an empty up car until the down service demand becomes sufficient to become a special service demand or, in other words, where there is -a down service demand at not only one floor but at several floors, so that the plurality of unanswered down calls become a special service demand. The quota relay Q is provided for this purpose and eiects it by counting the number of iioors at which a down call exists, and, when they exceed a predetermined number by then rendering efective the auxiliary circuit 5l controlled by the service demand relays to cause the next unloaded up car to answer such special service demand.

The quota relay Q may be connected to the down call registering means for each floor if desired but usually it is found to be preferable to connect the relay Q to the down call registering means of only a selected group of the lower floors which may be called a service demand zone.

In the present instance, the service demand zone has been selected as including the 2nd, 3rd, 4th and 5th oors. The energization of the quota relay is controlled by a plurality of branch circuits, one for each floor in the service demand zone and each of which includes a quota resistor, such as R2, controlled by contacts operated by the down door call relays, such as 2DR, in the service demand zone. The quota relay and the resistors, together with their connections, should be so proportioned that the relay will be responsive to a predetermined quota of registered down calls in the service demand zone.

For example, as long as no down call is registered in the service demand zone, the relay Q will not be energized. If only one down call in the service demand zone is registered, relay Q will still remain unoperated because sulcient current will not now through the one resistor to actuate relay Q. But, assuming a. quota of two, as soon as two down calls in the service demand zone are registered, suicient current will now through the two resistors in parallel to actuate relay Q.

y"Ihefz resistor circuit: 'Ifor `the Vthri fioorincludes: atmanually operativefiswitchplf;so-that the sys# tennmay be easily' adjustedrto includeor :exclude theth floorfrom-the groupof-efloors selected as the service demand iioors foncontrolling therelay Q; Similarswitchescmay beincluded in the other `resistor circuits leadingto relay Q. if; de;

sirerlyi Iii it is desired vatv any time to'-'operate the sys'- tacts QI and thereby rendering: theerelay'Q. in'- eiective to controlvthe circuit 5I.

. Although the present "illustration ishowsi the quota relay Q as connected for a service demand zone. comprisingL the.down"stop callsf. at the' 2nd, 3rd, 4th, and 5th floors, it will bereadily vapparent thatr any4 desired floors may bei.-includ'edfor exe.

eludedy from the servicedemand zone; Itwill also;

be apparent,thati the: serviceY demandsystemmay bey readily'applie'dvto the up direction ,stop calls so that a service demand in the up directiorr will effect the stopping. and'y reversing. oft an empty down scar, ifi desired..

Ifthe car attendantidesiresjor any reason, to go above the highestfdownzcall or; above any ser;rv vice demandfcall Ywhile oni'zanupttrip', .he can ydo so by pressing a cara-call button for a'oor above, such as the top floor, tot causethe car to keep on up to such floor. Hecan ,alsorender' hiscar eX- empt from service demand operation by pressing the top 'licor-car button each Ytimezhe .startsifrom the parking floor.

Operation' ofi high'- call.reversalV i It will be assumed that'cars AandaB are standing at the lower terminal with the doors (not shown) closed and with no stop callsvregistered.. Under these conditions, the up ldirectionprefera ence relay Wof car A-is energizediby the-circuit L+I, D5, X2, J2, W. 28T, L-I-.. The up direction preference relay `BW of"A car B is energized by a similar circuit.. The switchVV 58 .inf-the auxiliary high call circuit 5I- (Fig. 5) is open to Arender the' quota relay Q effective toy .cause 'an iunloaded :up car to reverse in response to the by-pass' of a down call when a lpredetermined quota'of down calls. say two exists in the low zone.

. It will be assumed now lthat waiting down pase sengersA at the 4th and'6th`iioors operate the. down call buttons dD'and 6D to 4registeradown stop calls thereat;

The operation of the button-4D energizesthe relay ADR byfrhe -circuit 'L+3, 4D, 4DR.r iii), 6I, L-3 to close its self-holding contactsy ADRI and to energize thestopp-ing segments g4 and B94 testen-the nextccwn car. The relaygltDlt` also opens itsccn'fects DB2 inthe high-call circuit to preventoperation of vthehighiloor call relays and BKK The energized 'relay 4DR also closes its contacts -4DR3- in the circuit, of @quota relay Q` but-it does not operatef'forthatf 'one call.:

The operation of huttonrSD energizeslthe relay liDRbyy the circuitML-l-v',DglDR,Y 60,: 6I,\L`3. The energized'relay- DRy closes its contacts SDR IV to' supply energy to itsy self-holding circuit and to f the contactzsegm'ents gliv and'BgEtozstop the next clown'approa'ching car. The operated relay EDR also opens its. ycontacts- GDRZ` :in .the high call circuiti for: preventing operationofthe high floor CalLreIays1K-T andBKl Itmviilibe assumed-*now that the attendant in car ALcloses. the car switch CS temporarily to startV` thefcarf. upwardly: and thereby energizes the up directionswitch'Uand the .car running relay M through vthe circuitxLfl-LiCS, CSI, WI, FI, STU;

tacts U6 tolstartthe car upwardly;r The closing.

ofzcontaictsxU I energizes the brake` coil 2(1"to :re-

lease the brake'ISiFig. 3). .The closing of;thet j contacts 1LT2-anduU3fenergizes'rthe` eld windingj GEbyvth'e .circuit L.- l-I,U2, GF; U3, RI,^L--I.` The .energizationfoi'the' eld winding GF causes:

the:,generator;to supply energy tothelhoisting,mol--4 tor; lf-ffor: operating thedrum JI I- to :movie .can-Af.

upwardly.

The closing-lof, thescontactszUII energizesfthez. high speedrelay vV bythe circuit L+ I, U4,"VTU; El, V, Lf Il. The energized relay- Vcloses its' con-- tacts- VI therebyshorting the resistor RI vin the: circuitv Aof the-generator `eld Winding GF, kthus: increasingthe energization ofthe yileld winding. so that the motorl 4 nowmoyes thecarupwardlyy atqitsnormal high speed.

As .car `A vmoves upwardlyf with :no calls regis tered above it exceptsthedown:callsnat the 4th. and 46th floors, and^approa`ches--the'6th oor, its brushed engagesthe energized contactl segment; dizand :thereby Aenergizes thexhigh floor call relay: Krfbyr:A the 'circuits LTI-5,: 'I'DR2,v BURZ, d6', 34,1K; L-5. The energized relay vK closes its contacts KI and thereby energizes the high call reversing relay Jfbywthefcircuitzz Lei-5,' J, HI', KI, W1, 21B, L-5.

' The-energized relayv J closes its' contacts -J I (Fig-13% thereby`- energizing the slow-down? in duc'tbr relay andftl'ie inductor holding relay Gfbyl'the circuit L`|I ,'JI, Gf and-E in parallel, M'Ig'LL-I-fto elect-'dece1eraticn'of the car for'y the down call'stoprat-the-th floor, The rela-y.

f- Gjlin turn; closesfits' contacts -GI lto hold thev thus deenergizing'thehigh speed relay V. The relayVopens vits contacts VI thus restoring the`l resistor RI-to the-circuit of the generator eld winding-:'GFfand.- thereby-decreasing the speedof the hoisting motor-I4 and slowing down the car." Thef-relay1f'V also closes its contacts V2, thus energizing v the stopping "relay" F by'r L-I- I, Gf! V2, F,'MI Ile-I.

Ascar'A A-approaches' stillv closer to the 6thy oor,-it's --stopping relayQF-comes opposite the up Stopp-ing Aplate UFP for that floor which opensl its contacts FI. thereby deenergizing thecar running relay M and' the-up direction switchU.

The switchlU "opens its contacts UI inthe brake circuit andfit'srcontacts-UZ andUSfin the cir-AU cuit cl Vthefgenerator eld winding` GF, thus;

stopping-the car and applying the vbrake tohold it at the 6th floor.

At the sarne-time,-y theecontacts J2; of the en`v ergi'zed-high' call reversing relayJ are openin` one of'theparallel ycircuits of'the rup, direction preference relayfW; Therefore, when the con:v

tacts-'-M2f"of the foar runningrelayM open forl the 6th oor stop, they open the oher parallelv circuit-forthe relayfVV and thusr deenergiz'e Viti The deenergizedrrelay W-= thereuponfcloses' its* back contacts W2 which energize the down preference relay X by the circuit L-l-I, U6, W2, X, 28B, L-I. The energized down preference relay X closes 'its contacts XI in the circuit of the down direction switch D so that the next operation of the car switch CS will start downwardly.

The energization of the down direction relay X also closes its contacts X6 thereby energizing the cancelling coil SDRN bythe circuits L|3, SDRI, BDRN, f6, 40 X6, M4, L-3. The energized coil BDRN deenergizes the relay GDR and thereby cancels the down call at the 6th floor.

It will be assumed now that the waiting down passenger at the 6th oor enters the car and that the attendant closes the car switch CS thus energizing the down direction switch D and the car running relay M by the circuit L+ I, CS, CSI, XI, F2, STD, D, M, 23, LI. The energized switch D closes its contacts DI, D2, D3 and D4 and opens its contacts DE. The closed contacts D2 energize the brake c0112!! to release the brake I5. The closed contacts DI and D3 energize the ield winding GF by the circuit L-i-I, D3, GF, DI, RI, L-I which causes the generator to supply energy to the hoisting motor I 4 to start the car downwardly. The closed contacts D4 energize the high speed relay by the circuit L+I, D4, VTD, E2, V, L-I to close its contacts VI around the resistor RI, thus causing the car to move downwardly at high speed.

The foregoing description demonstrates how a car will operate on an up trip under normal conditions to reverse itself at the highest down call when there are no up calls above it to be answered.

Operation of special service demand It will be assumed now that car A continues downwardly, passes the 5th oor and approaches the down stop call at the 4th floor. As car A approaches the 4th floor, its down brush 42 engages the contact segment g4, thereby energizing its stopping relay S by the circuit L+3, 4DRI, g4, 42, X5, S, 21a, L-3 to stop it at the 4th floor. The energized relay S closes its contacts SI, thereby energizing the decelerating inductor relay E and the inductor holding relay G by the circuit L+ I, SI, G and E in parallel, MI, L-I. As car A approaches closer to the 4th oor, its inductor relay E comes opposite the down plate DEP for that floor, thereby opening its contacts E2 to deenergize the high-speed relay V. The deenergized relay V opens its contacts VI, thereby restoring the resistor RI to the circuit of the generator eld Winding GF and thus decreasing the speed of the hoisting motor I4 and slowing down the car. The relay V also closes its back contacts V2, thus energizing the stopping relay F by the circuit L-I-I, GI, V2, F, MI,LI.

As car A approaches still closer to the 4th iloor, its stopping relay F comes opposite the down stopping plate DFP for that oor, which opens its contacts F2, thereby deenergizing the car-running relay M and the down-direction switch D. The deenergized switch D opens its contacts D2 in the brake circuit and its contacts DI and D3 in the circuit of the generator field winding GF, thus stopping the car and applying the brake to hold it at the 4th floor. The deenergized relay M closes its contacts M4 thereby energizing the cancelling coil 4DRN by the circuit L+3, 4DRI, 4DRN, f4, 40, X6, M4, L-3 for deenergizing the relay 4DR to cancel the 12 down stop call at the 4th floor. The deenergized relay 4DR opens its contacts 4DR3 in the circuit to the quota relay Q and closes its contacts 4DR4 so that it now has no effect on the service demand relays.

It will be assumed now that car A takes on so many down passengers at the 4th iloor that it cannot accommodate any more passengers, and that the attendant in that car therefore operates his bypass button 21 to bypass any down calls registered at the floors below. The button 21 may be held in by the operator as long as he desires to bypass top calls or it may be of the type which will hold itself in until the car arrives at the 1st floor.

The pressing of the bypass button 2l opens its contacts 21a and its contacts 2lb and closes its contacts 2'lc. The opening of the contacts 21a prevents the stopping relay S of car A from being operated by the down stop calls at the oors below so that the car will now pass such calls Without stopping and will proceed to the lower terminal, unless the bypass button is released to again permit the car to pick up down stop calls.

The opening of the contacts 2lb prevents operation of the high-call reversing relay J of car A while it is on either an up or a down trip. Hence the bypass button may be used to bypass calls on an up trip as well as on down trips.

The closing of the contacts 21e energizes the service demand relay 4Y by the circuit L+5, 2lc, V3, 43, i4, 4Y, 62, L-G, The energized relay 4Y closes its contacts 4YI in the circuit 64 and opens its contacts 4Y2 in the auxiliary circuit 5I t0 prepare for the stopping and reversing of the next unloaded up car at the highest down call below the floor at which the bypass button was operated, whenever a quota of unanswered down calls exists in the quota zone. The energized relay 4Y also closes its self-holding contacts 4Y3 so that it will remain energized until its cancelling coil 4YN is energized by an unloaded up-moving car` stopping and reversing in answer to the bypass operation.

The arrival and stopping of car A at the 4th floor also causes its down brush 40 to engage the contact segment f4 and thus energizes the restoring coil 4DRN by the circuit L+3, 4DRI, 4DRN, f4, 40, X6, M4, L-3 to cancel the down call at the 4th oor by deenergizing the relay 4DR. The deenergized relay 4DR recloses its back contact 4DR2 in the circuit 50 and recloses its back contacts 4DR4 in the circuit 63 of Fig. 5.

It will be assumed now that the attendant in car A closes the car switch CS, thus energizing the down-direction switch D and the car-running relay M, as `described before and the car starts downwardly.

At this point in the operation, it will be assumed that a new down call is registered at the 6th floor and that calls are also registered at the 3rd and 2nd oors by waiting passengers pressing the down lbuttons SD, 3D and 2D.

The pressing of button 6D registers a down call at rthe 6th iioor in the same manner as the previous down call at that iioor.

The operation Iof button 3D registers a down call at the 3rd oor by energizing the relay 3DR. by the circuit L-l-3, 3D, 3DR, 6D, -6l, L-3 to close its contacts 3DR! to supply energy to its self-holding circuit and to the stopping segments g3 and B93 to stop the next `down car. 'I'he energized relay 3DR also opens its contacts 3DR2 in the high call circuit 50 for preventing operamagna Z-ILRL'M thai-high? yca'll icirouiti f5 it a andiciosestits: conta ZDRS-sin' thezcirhuititoftheca'elay Q25 The registrazioni or; thezdowm'cali. IaiaJthefzZnd: floor in addition to the down call at the Srftsiioon completes? the/quota foriatspeciai.'serwi'oeiidmand befo'acusetheirclosedscontya'ctsZDR:.completeza#cirer cnitithrongh hecresistori .'RZtztoz the :quotenrelay` QLSJ. Iriasmuc' il cnrrentrcan nowlz-flwrthrough thetsresistors xlftfbrrnd :RE 'im parametro :thesrelayz Qgritsrwiilsfreceive suflcientrcurrent; tot"y energize it andiicause .'itftofclose rits?` contctsfQl im ther amdiiaryf circuit" .51v isoitthatcthesnext un1oaded ixpmarrrvwiihstoprat the-rhighes downrcaifi lcelcav th'erilohr ratfwhicla zthexafibypass shirt-toni 2i" was;` operated.

It twill: loe assumed: nowrthaia :carum'movesffonx down to the 1st oor without answering the dorwni: oalls :ati ,the zr-31h11 'and Zudiorsv and thati'ecarf. B szstirrtedxonits rtripbyrthfattendant thereinclosin'gfh'sacazrswitch fBGSf The ccio'sing oif'thez switchiBGSrenergizesather 11o-direction .fswito'h'cBU -fandtthecarrmlning relayI BM of oar B in the same manner astdesoriberieinf connection with car Agilan'd'nicarff. mowcfm'oves upwastdhatnormaltspeedf: l

A ca approaches fmorercloselyntozthecrd` floor, fit lrringsi-its induotnrfreiay BEziopposi1ie rits; un inductor plate UEP for the Sdoonfthus" cfasingftnef-reiay can tof open-f its; contaetsiinl The opening-ofthe 'contacts EBE! deenergfizes the higi'i-sp eed-`reiay 'BVfL which in lturn opens its con" tacts BVi "and dr-thus' restoresr .theV resistor-"BR}i to' thecirouit ofthe generator BG; thus'd'etel'erat`m` ing-the; car.' The deenergized relay 4BV aisovcloses its; contactsA BV2 and thereby Lenergizesv the 4stop-4 pngqindlctor relay BEST A'ScarB decelerates and approaches closer to the 3rd floor, it'. brings. itsstoppng. freiay. BE `adm jacentb thenp stonpingwplate BUFP' forctherd or, which, causes the@ ont acts-j k1311" If, to open :and thusrdeenergize -1the11p-,directioni switch BIJ and the car-runningurelay BlVLlofV cariy B. i. Theffrelay; BU penshits contacts-BU-tand'BUdwinfthegena erators-eiid'fwindingrBGF anditszcontactsf] Irin` thmcirouitssof itheacbrakezf-coirliw; .thixsxrstnmrngi Inasmuchfasathe contacts BJ'Zfare openiinsther cilhuitl of the' :upf-direction' ypreferencerelay thenopeningf oithe contacts BMZ when rtherrelayi decnergized also Vdeonergizes:the'v -roltW-BWek which',thereuponfclosesitsf-back lcontactsfBWinl theffcirouit of the downedreotion relay E'fXgthilsy energizing that relay hy the circuit Lfl-2,v.,BU6,-,; BWQZgBX, B28B; 'Lf-2; Car B isnow--stoppedfat therrdffl'oor and its direction preference relaysA BWf'andfBX yhave 'beenreversed so that theynexir time vcar B. is :started it will move linthe down: direction.

It shouldi also;` loeobserved'f that V- inasmuch asv car Aihas arrived 'and stopped yin the updirectioni at the 3rd floor and its high call reversingrelayr J wasooperated 'toxstop yit and reversefit :atl that oori-.zitf also energized'fthe neutralizing Y; coil AYN= BfBJfBV, BWQ, L- ii. The energizationof the; neutralizing coil @YN canc'eisfthe service demandi set up by the energizaton of the coi^l-dYythusfs ca-usingf itf lto fopenits .'selffhoiding- ,contacts-4Y3, open,its contacts AY! andclose-itsicontaotsf4Y2 in fconneotonfwith the demand-circuit 5 I ltheree byc'restoring-circuit 5 I,- tof its .l normalM condition:

It will loef-assumed -now that car B takes on the downLpa-ssengers ,at the 3rd fioorwandzthatnthel. attendantI closes `thevswitch BCS, whereupon ica-.n Ba.starts^downward1y stops at the: 2nd. floors-to;- answerA the down. call ,thereat `and 'then ,moveseon-l down to the lower terminal.

Bythis operation, vitrwlilfloe observed that when a vdoxtrxncan makes a bypass-ingoperationg. it. can. cause .tannin-moving... car to, stop andk reverseto` takeon .do.wn passengers. at the highestdown. calllhelwthe flonat which the bypassing,opera?E tion tookplace when a Y .predetermined service demand lfexists,. thereby .giving prompt 2sarilke to, th:.various;f1oors served by the elevatorJ cars.

Operation ofgbypasszng'without quota" ItT -wi'l'liV be* assumedA now lthat the switch 58*in thet circuit* 5 I (Fig. 1 5)' is closed to render-'the quotareia'y Q ineffective; so'that a bypassing `opY` eration-fliy-'anydownlcar will cause the next-un:

ladedfupcar tostop and:reverseY at" highest" downv cali blowftheifioorlat which thefbypassfop'-Y eration tookfplace.`Vv

ItT'wi-ll be assumed l'fi'irtherthat car B'is stand ing at the lower terminali that car A isistandingl ati-.ther upp'err-terrrrinal` and? that' fdciwn` stopl calls areLregfi'stered"atiithe "6th f oor `and ther 4th floor byisthepassengers :rthereat s operating the down: buttml-Dland ADL? Tl'iewoperetionwof the( but-- GD'Land, #Dr register' 'down stop'. cai-ls'. fat ."the 4th oonzan'ct 6th floor; in the manner:Y previouslyl described.

Itwilleberasslmiedalso that "car A moves: downf ca-:and vstops-"at 4the 6th ,fic'or and that iteta'kesfzonf sommanyvpassengerszxat that' oorfzthat thefat-V tendant presses:hisxbypasswbutton:21: scfflthatrhi's canwilllnotmakofanymore down stopsfonadri-ili tional-l passengers: s

The operation of the bypassV button 2 7 V"opensr itswontacts .f2.1 a, ani- 2 111.1 and 1 closesz` its contacts: 21h. y The: opening :pithe contacts f21hrlrprevents; the stopping relay S of car A from being operated: Icy; downrstop rcallsifaia the .ioorsloelow :so athatsthe carifwillimowrpass such fca'ils :withoutstopping-V Thempeningfofs .the :contacts iiibl'prevents opera@ tion: tithe highicalbreversingfrelay1T Jof'lcar -As ffclosingfoftthe contactsl '2 Tc Aenergiz'esther servicialdemandreiayesrby;the fcircuitiill-, 21

V3, 43, i6, BY, 62, L-G. The energized relay BY closes its contacts BYI in the circuit 66 and opens its contacts 6Y2 in the auxiliary circuit 5| to prepare for the stopping and reversing of the next unloaded up car at the highest down call below the 6th floor. The energized relay 6Y also closes its self-holding contact BY3 so that it will remain energized until its cancelling coil 4YN is energized.

The stopping of the car A at the 6th floor also causes its brush 40 to engage the contact segment f6 and thus energize the restoring coil GDRN by the circuit L-I-3, BDRI, BDRN, f6, 4D, X6, M4, L-S, to cancel the 6th i'ioor down call. The deenergized relay BDR recloses its back contacts 6DR2 in the circuit 50 and its contacts BDRS in the circuit 63.

It will be assumed now that the attendant in car A closes the car switch CS thus energizing the down direction switch D and the car running relay M as described before to run the car on down to the ist floor, bypassing the stop call at the 4th iioor.

It will be assumed now that waiting passengers at the 7th oor operate the button ID to register a down call for that floor. The operation of the button 'ID energizes the down direction relay IDR by the circuit L-i-S, 1D, TDR, 6I, L-3. The energized relay IDR closes its self-holding contacts IDRI, opens its contacts 'IDR2 to prevent operation of the high oor call relays K and BK. There are now down calls registered at the 7th and the 4th floors.

It will be assumed that the attendant in car B closes his car switch BCS and thereby starts car B on an up trip in the same manner as previously described. As car B approaches the 4th iloor, its selector brush B34 engages the contact segment B114 and thereby energizes its high floor call relay BK by the circuit L-I-5, 58, BYI, 66, 6DR2, EURI, DR2, 4URI, Bd4, B34, BK, L-6. The energized relay BK closes its contacts BKI thereby energizing the high call reversing relay BJ by the circuit L-I-S, BJ, BHI, BKI, BWI, B21d, L-G to close its contacts BJI and BJ 3 and to operate its contacts BJ 2. The closed contacts BJ3 complete a self-holding circuit for relay BJ. A closed contact BJI energizes the decelerating relay BE and the inductor relay BG of car B by the circuit L-I-Z, BJ I, BG and BE in parallel BMI, L-2.

As car B approaches more closely to the 4th oor, its inductor relay BE meets the up inductor plate UEP for the 4th floor thus opening its contacts BEI. The open contacts BEI deenergize the high speed relay BV to open its contacts BVI and thus restore the resistor BRI to the circuit of the generator BG, thus decelerating the car. The deenergized relay BV also closes its contacts BV2 to energize the stopping relay BF. As car B approaches closer to the 4th floor, its stopping relay BF meets the up stopping plate BUFP for the 4th floor which opens its contacts BFI and thus deenergizes the up direction switch BU and the relay BM. The relay BU opens its contacts BU3, BU4, and BUI thus applying the brake BI5 and deenergizing the motor to stop the car at the 4th floor.

Inasmuch as the contacts BJ2 are open, the opening of the contacts BMZ when relay BM is deenergized also deenergizes the up direction relay BW which thereupon closes its back contacts BWZ and energizes the down direction relay BX. Car B is now stopped at the 4th floor and its 16 direction relays BW and BX have been reversed so that next time car B is started it will move in the down direction.

It should also be observed that inasmuch as car B has stopped in the up direction at the 4th iloor and its high call reversing relay J also operated to stop it and reverse it at that floor, the engagement of its brush B35 with the contact segment Be4 energizes the coil GYN by the circuit L-I-5, 65, 6Y3, GYN, BDRS, 5DR4 Bel, B35, BJI, BV4, BW9, L-S. The energization of the cancelling coil GYN restores the service demand relay BY to its normal condition.

It will be assumed now that car B takes on the down passengers at the 4th oor and that the attendant closes the switch BCS whereupon car B starts downwardly and runs down to the lower terminal.

By this operation, it will be observed that, when a down car makes a bypassing operation, the next unloaded up moving car will stop and reverse at the highest down call below the floor of the operated bypass and that in making such stop it will cancel the bypassing demand and restore the service demand relay to its normal condition.

By the foregoing operation, it will be seen that I have provided an improved system of call control for elevator cars which will cause them to render service in accordance with the ordinary and the specific demands of service at the various oors.

Although I have illustrated and described an elevator control system embodying an example of my invention, it is to be understood that modifications thereof and changes therein may be made Without departing from the spirit and scope of the invention.

I claim as my invention:

1. In a control system for a plurality of elevator cars operable past a plurality of iloors, each car being provided with means to start said car and to continue said motion when started, the combination of a down switch associated with each of said floors and common to said cars; means associated with each car, responsive to an actuation of any combination of said down switches for stopping any car on its down trip at the floors associated with the actuated down switches; a by-pass switch for each car; means responsive to actuation of the by-pass switch of a down car for rendering the stopping means of that car unresponsive to actuated down switches on its down trip; and means responsive to said actuation of said by-pass switch for stopping another car on its up trip at one of said floors at which a down call has been bypassed by the operation of said by-pass switch.

2. In a control system for a plurality of elevator cars operable past a plurality of floors. each car being provided with means to start said car and to continue said motion when started, the combination of a down switch associated with each of said floors and common to said cars; means associated with each car, responsive to an actuation of any combination of said down switches for stopping any car on its down trip at the floors associated with the actuated down switches; a by-pass switch for each car; means responsive to actuation of the by-pass switch of a down car for rendering the stopping means of that car unresponsive to actuated down switches on its down trip; means responsive to said actuation of said by-pass switch for stopping another car on its up trip at one of said oors at which a down call has been bypassed by the operation of said by-pass switch; and a quota means common to all ci the cars and controlled by a predetermined number of actuated down switches for preventing the stopping and reversing operation of an up car in response to an actuated by-pass switch until a predetermined number of down switches are in actuated condition.

3, An elevator system comprising a plurality of cars for serving a plurality of floors, an operating means for each car, a reversing means for each car, an up call device and a down call device for each iioor for causing the operating means of any car to stop it thereat when it is in condition to make such stop, a servicefdemand device for each floor, a by-passdevice for each car, means responsive to operation of a by-pass device on a down car for operating a service demand device, and means responsive to operation of a service demand device for causing the operating means and the reversing means of an up moving car to stop it and reverse it.

4. An elevator system comprising a plurality of cars serving a plurality of iioors, an operating means for each car, a reversing means for each car, an up call device and a down call device for each floor for causing the operating means of any car to stop it thereat when it is in condition to make such stop, a service demand device for each floor, a by-pass device for each car, means responsive to operation of a by-pass device on a down car for operating a service demand device, means responsive to operation of a service demand device for causing the operating means and the reversing means of an up moving car to stop it and reverse it, and a quota means common to all of the cars and operable by a predetermined number of down call devices being in operated condition for preventing operation of the stopping and the reversing means of an up moving car in response to operation of a service demand device until a predetermined number of down call devices are in operated condition.

5. An elevator system comprising a plurality of cars serving a plurality of floors, an operating means for each car, a reversing means for each car, an up call device and a down call device for each iioor for causingthe operating means of any car to stop it thereat when it is in condition t make such stop, a service demand device for each floor, a bypass device for each car, means responsive to operation of the bypass device of a car for rendering the operating means of that car unresponsive to operated call devices yahead of it, means responsive to operation of a bypass device when its car is making a down stop at a iioor for operating the service demand device for that iioor, and means responsive to operation of a service demand device and the call devices for causing the operating means and the reversing means of an up moving car to stop and reverse it.

6. An elevator system comprising a plurality of cars serving a plurality of iioors, an operating means for each car, a reversing vmeans for each car, an up call device and a down call device for each floor for causing the operating means of any car to stop it thereat when it is in condition to make such stop, a service demand device for each floor, a bypass device for each car, means responsive to operation of the bypass device of a car for rendering the operating means of that car unresponsive to operated call devices ahead of it, means responsive to operation of a bypass device when its car is making a down stop at a iioor for operating the service demand device for that floor, means responsive to operation cf a service demand device and thecalldevices for causing the operating means and the reversing means of an up moving car to stop and reverse it at the highest down call below the operated service demand device, and means responsive to the stopping and reversing operation of said up'moving car for restoring the operated service demand device to its unoperated condition.

'7. In a control system for a plurality of elevator cars serving a plurality offioors, a starting means for each car, a stopping means for each car, a reversing means for each. car, an up call device and a down call device for each floor for causing the stopping means of the cars to stop them thereat When they are'rin condition to make such stops, a service demand device for each iioor, a by-pass device on each car operable to eiect operation of the servicedemanddevice for a floor when that car stops atthat floor, a circuit responsive to operation of aservice demand device for causing operation of the stopping and the revers- Ying means of an up car at the highest operated down call device at orbeloW the floor of the operated service demand device, and a quota means common to al1 of the cars and controlled by a selected group of down call devices and operable by a predetermined number of down call devices in said group being in operated condition for preventing operation of said circuit until a predetermined number of unanswered down calls accumulates in said group.

8. In a control system for a plurality of elevator cars serving a plurality off floors, including a service demand Zone of OQIS.- a starting means for each car, a stopping means for each car, a reversing means for each car, an up call device and a down call device for each floor for causing the stopping means of the cars to stop them thereat when they are in condition to make such stops, a quota means common to all of the cars and operable by a predetermined number of down call devices in the service demand zone being in operated condition, a service demand device for each floor, a bypass device oneach car for causing that car to bypass stop calls ahead of it, means responsive to operation of the bypass device of a car at a floor for operatingthe service demand device for that floor, and vmeans responsiveto operation of the quota means anda service demand device for causing operation of the stopping and the reversing means of an up'moving car at the highest operated down call device at or below the oor of the operated vservice demand device.

9. In a control system for a plurality of elevator cars serving a plurality of oors, a starting means for each car, a stopping means for each car, a reversing meansfor each car, an up call device and a down call device for each floor for causing the stopping means of thecars to stop them thereat when they are in condition to make such stops, a quota means common to all of the cars and controlled by a selected group of call devices in one direction and operable by a predetermined number of call devices in said group being in operated condition, a service demand device for each oor, a bypass device on each car, means responsive to operation of the. bypass device of a car at a floor for operating the servicedemand device for that floor, a high call circuit controlled by the up and the down call devices, .an auxiliary circuit operable by the quota means and a service demand device, and a high call above device for each car responsive to operation of the auxiliary circuit and the high call circuit when that car is approachmg in direction opposite to said group of call devices for causing operation of its stopping and its reversing means to stop it and reverse it.

10. An elevator system comprising a plurality of cars serving a pluralityA of floors including a service demand zone, an-.operating means for each car, a reversing means for. each. car, an up call device and a down call device v:for each floor for causing the operating means of any car to stop it thereat when it is in condition to make such stop, a quota means commentoV all the cars, means responsive to a predetermined number of down call devices in the service demand none vbeing in operated condition for operating the quota device, a service demand device for each floor, a bypass device for each car, means responsive to operation of the bypass device of a car for rendering the operating means of that car unresponsive to operated call devices ahead ofit means responsive to operation of a bypass device when its car is making a down stop at ancor for operating the service demand device for that oor, means responsive to operation of the quota device and a service demand device and the call devices for causing the operating means and the reversing means of an up moving car to stop and reverse it at the highest down call at or below the operated service demand device, and means responsiveV tothe stopping and reversing operation of said up car for restoring the operatedv service demand device to its unoperated condition.

11. An elevator system comprising a plurality of cars serving a plurality of floors including a service demand zone, an operating means for each car, an up call device and a down call device for each floor for causing the operating means of any car to stop it thereat when -it is in condition to make such stop, a call above circuit, means responsive to operationV of the call devices for controlling the call above circuit, car reversing means for each car responsive to the condition of the call above circuit for stopping and reversing that car at the highest down call', a/quota means common to all the cars, means responsive to a predetermined number of down call'devices in the service demand zone being in operated condition for"A operating the quota device, a'service demand device for each floor, a bypassy device for each car, means responsive to operation of the bypass device of a car for rendering the operating means of that car unresponsive to operated call devices ahead of it, means responsive to operation of the bypass device of a car when it is making a down stop at a oor for operating the service demand device for that floor, meansv responsive to operation of the quota device and a service demand demake such stop, call-above circuit, means respony' sive to operation ofthe call devices for controlling the call-above circuit to register operation of the call device, acar reversing means for each car responsive to the condition of the -call-above circuit for stopping and reversing that car when unloadi ed and up-traveling at the highest down call, a quota means common to all the cars, means responsive to a predetermined number of down call devices in the service demand zone being in operated condition fo; operating the quota device, a-

service demand device for each door, a bypass device for each car, means responsive to operation of the bypass device of a car for rendering the operating means of that car unresponsive to operated call devices ahead oi it, means responsive to operation of the bypass device of'a car when it is making a down stop at a floor for operating the service demand device for that oor, means responsive to operation of the quota device and a service demand device and the condition of the call above circuit for causing the operating means and the reversing means of an unloaded up moving car to stop it and reverse it at the highest down call at or below the floor of the operated service demand device, and means responsive to the stopping and reversing operation of said up car for restoring the operated service demand device to its unoperated condition.

13. In a control system for a, plurality of elevator cars serving a plurality of floors, including a service demand zone of iloors, a starting means for each car, a stopping means for each car, a reversing means for each car, an up call device and a down call device for each floor for causing the stopping means of the cars to stop them thereat when they are in condition to make such stops, a quota means common to all of the cars and operable by a predetermined number of down call devices in the service demand zone being in operated condition, a service demand device for each floor, a bypass device on each car for causing that car to bypass stop calls ahead of it, means responsive to operation of the bypass device of a car at a floor for operating the service demand device for that floor, a high call circuit controlled by the up and the down call devices, an auxiliary circuit controlled by the quota means and a service demand device, a high call above device for each car responsive to the condition of the auxiliary circuit and the high call circuit when that car is an unloaded up moving car for causing operation of its stopping and its reversing means at the highest operated down call device at or below the floor of the operated service demand device, and means responsive to operation of the stopping and the reversing means of said unloaded car for restoring the operated service demand device to its normal condition.

14. An elevator system comprising a plurality of cars for serving a, plurality of floors including a service demand zone, a starting means for each car, a stopping means for each car, a reversing means for each car, an up call device and a down call device for each iioor for causing the stopping means of the cars to stop them thereat when they are in condition to makesuch stops, a high call circuit controlled by the up and the down call devices, a high call above device for each car responsive to operation of the high call circuit when that car is an unloaded up moving car for operating its stopping and the reversing means at the floor of the highest operated down call device, a quota means common to all of the cars and operable by a predetermined number of down call devices in the service demand zone being in operated condition, a service demand device for each i'loor, a bypass device for each car, means responsive to operation of the bypass device of a car when it makes a down stop ata oor for operating the service demand device for that oor, an auxiliary circuit responsive to operation of the quota means and operation of a service demand device for operating the high call above device of an up moving car to cause operation afie'ase -rA 21 of the stopping and the reversing means of that car.

15. An elevator system comprising a plurality of cars for serving a plurality of iioors including a service demand Zone, a starting means for each car, a stopping means for each car, a reversing means for each car, an up call device and a down call device for each floor for causing the stopping means of the cars to stop them thereat when they are in condition to make such stops, a high call circuit controlled by the up and the down call devices, a high call above device for each car responsive to operation of the high call circuit when that car is an unloaded up moving car for operating its stopping and the reversing means at the iioor of the highest operated down call device, resistor circuit associated with each down call device at each floor in the service demand zone, a quota means common to all of the cars and connected to the resistor circuits and operable by a predetermined number of down call devices in the service demand zone being in operated condition, a service demand device for each floor, a bypass device for each car for rendering the operating means of that car unresponsive to operated call devices, means responsive to operation of the bypass device of a car when it makes a down stop at a floor for operating the service demand device for that floor, and an auxiliary circuit responsive to operation of the quota means and operation of a service demand device for operating the high call above -device of an up moving car to cause operation of the stopping and the reversing means of that car.

16. An elevator system comprising a plurality of cars for serving an upper terminal floor, a lower terminal iioor, and a plurality of intermediate floors, a starting means for each car. a stopping means for each car, a reversing means for each car, an up call device and a down call device for each intermediate floor for causing the stopping means of the cars to stop them thereat when they are in condition to make such stops, a high call circuit controlled by the up and the down call devices and common to all the cars, a high call above device for each car responsive to operation of the high call circuit when that car is an unloaded up moving car for operating its stopping and the reversing means at the floor of the highest operated down call device, a plurality of resistor circuits and means for adjustably connecting them for a plurality of floors to dene a service demand zone, a quota means common to all of the cars and connected to the resistor circuits and operable by a predetermined number of down call devices in the service demand zone being in operated condition, a service demand device for each floor, a bypass device for each car for rendering the operating means of that car unresponsive to operated call devices, means responsive to operation of the bypass device of a car when it makes a down stop at a floor for operating the service demand device for that oor, an auxiliary circuit responsive to operation of the quota means and operation of a service demand device for operating the high call above device of the next unloaded up moving car to cause operation of the stopping and the reversing means of that car at the highest operated down call device below the floor of the operated service demand device, and means responsive to operation of the stopping means and the reversing means oi said unloaded car for restoring the operated service demand device to unoperated condition.

17. In an elevator system for a building having a plurality of floors including an upper terminal floor and a lower terminal floor, a plurality of elevator cars for serving the floors, operating means for operating each of the elevator cars in either direction of travel between the terminal iioors, reversing means for each of the elevator cars, a call device for each of a number of said iioors cooperating with the operating means for stopping any of the cars at any floor at which the call device is actuated when the car is traveling in a predetermined direction between the terminal floors and is approaching the floor oi the actuated call device, a by-pass device for each of the cars, each of the by-pass devices being effective when actuated for preventing the associated car from stopping at a floor at which one of the call devices is actuated, and means responsive to actuation of a by-pass device on a rst one of the elevator cars traveling in the predetermined direction for conditioning a second elevator car traveling in a direction opposite to the predetermined direction to stop and reverse at a floor call by-passed yby the first car.

18. An elevator system as dened in claim 17 wherein when a plurality of floor calls are unanswered between the point at which the first elevator car initiated its by-passing operation and the terminal floor which is being approached at the time by the rst car, the last-named means is eiective for stopping and reversing the second elevator car at that one of said plurality of oor calls which is remote from the last-named terminal Hoor.

HAROLD W. WILLIAMS.

REFERENCES CITED The following references are of record in the 5 flle of this patent:

UNITED STATES PATENTS Name Date Williams et al Feb. 11, 1941 Number 

